The zebrafish, Danio rerio, has become widely accepted as a model for human disease. Small molecule screens have been performed to identify modifiers of vascular patterning but this process has been performed at relatively low throughput since the tools for fully automated processing are not yet available. We propose to develop a novel, high-throughput screening assay for angiogenesis promoters. The assay would be based on the use of the SideView microplate to collect clear images of the vascular pattern in animals that express GFP in their vasculature. During Phase I we: 1) developed novel methods to modulate angiogenesis promoters in the plexus; 2) developed software that locates the zebrafish, identifies the region of interest, and moves that region to the center of the field of view; and 3) developed automated, post-acquisition image processing software that distinguishes wild-type zebrafish embryos from xxx mutant embryos with deformities in the plexus. During Phase II the methods, software and instrumentation will be fully integrated and the assay will be validated in a model screen using the Prestwick Library of FDA- approved compounds.